<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    div{
      width: 200px;
      height: 150px;
      border: red 3px solid;
      /*外边距*/
      margin: 2px;
    }
  </style>
</head>
<body>
<div></div>
<div></div>
</body>
</html>